add a select callback on a clock from the search result

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
diff --git a/display.h b/display.h
index fe084cb..7fa5361 100644
--- a/display.h
+++ b/display.h
@@ -19,6 +19,7 @@
 	int (*display)(void);
 	int (*select)(void);
 	int (*find)(const char *);
+	int (*selectf)(void);
 };
 
 extern int display_print_line(int window, int line, char *str,